EFFECTS OF FLOOR TYPE ON SERUM FOLATES, SERUM VITAMIN B12, PLASMA BIOTIN AND ON GROWTH PERFORMANCES OF PIGS
Forty-eight 5-wk-old piglets were grouped into six blocks of eight pigs each. Each block comprised two pens of four pigs, two castrates and two females; one pen had a solid floor (free access to feces) while the other had a slatted floor (limited access to feces). Pigs were fed ad libitum a diet computed to meet NRC requirements for 18 wk. Every 14 d, each animal was weighed and a blood sample was taken for the determination of folates, vitamin B12, biotin, hemoglobin (Hb) and hematocrit (Ht) levels. There was no effect (P > 0.05) of floor type on serum folates or vitamin B12, nor on plasma biotin which averaged, respectively, 72.2 ± 2.9 ng mL−1, 246.0 ± 21.3 pg mL−1 and 1.34 ± 0.1 ng mL−1 at the end of the experiment. Biotin concentration was about 16-fold greater in the feces than in the diet, which was indicative of active bacterial synthesis of B-complex vitamins in the gut. Hb and Ht were about 4% higher (P < 0.05) in pigs on slatted floors than in those on solid floors. From 5 to 11 wk, pigs raised on slatted floors grew faster (P < 0.05) than those raised on solid floors, but growth rate was similar (P > 0.05) on both floor types from 11 to 23 wk. The results suggest that whatever the age of growing pigs, coprophagy is not an important way by which these animals meet their requirements in B-complex vitamins. Key words: Pigs, floor type, coprophagy, folates, vitamin B12, biotin